1. Department of Swine Diseases, National Veterinary Research Institute, 24-100 Pulawy, Poland
2. Department of Pathology, National Veterinary Research Institute, 24-100 Pulawy, Poland
3. Department of Pharmacology and Toxicology, National Veterinary Research Institute, 24-100 Pulawy, Poland
4. “Chiron” Veterinary Clinic, 09-410 Plock, Poland